#p  'grid.dat' w l lt 7, 

p "< gravlens sis.gl | grep '^[- ]'" w p ps 3 pt 5 t 'images', "<  gravlens sis.gl | grep '^[- ]'| head -1" w p ps 3 pt 5 t 'source' , 'cc.dat' w l t 'critica', 'cc.dat' u 3:4 w l t 'caustica'
